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BEST AVAILABLE COP 2'Sheets-Shest 1. W. E. SAWYER & A. MAN. Electric Switch.

No.'229,47 6. Patented June 29,1880.

N. Pm morcpumocmwuaz. WASHINGTON. 0 1.

BEST AVAILABLE COP I 2Sheets-Sheet-2. 'W. E. SAWYER & A. MAN.

Eleotr io Switch.

Patented June 29,1880.

FIG. 7.

W/T/VESSES.

N. PETERS. MIQLITHOGRAPNBL WASHINGTON.

UNITED STATES BEST AvAiLAeLE cor PATENT Erica.

WILLIAM E. SAWYER, or NEW YORK, AND ALBON MAN, or BROOKLYN, N. Y., ASSIGNORS ro ELEcTRo DYNAMIC LIGHT COMPANY.

ELECTRlC SWITCH.

SPECIFICATION forming part of Letters Patent No. 229,476, dated June 29, 1880.

Application filed Deember 5. 1878.

and of the manner and process of making,

constructing, and using the same, in such full, clear, concise, and exact terms as to enable any person skilled in the art orscience to which it appertains, or with whieh'it is most nearly connected, to make, construct, and use the same, reference being bad to the accompanying drawings, making part of this specification, and to the figures and letters of reference marked thereon, and also to Letters Patent allowed tons for switches for electric lights, November 15, 1878.

In this switch the mode of operation in itsrelation to the lamp is substantially the same as that of the Letters Patent allowed to us as aforesaid; but this switch differs from that in its mechanical construction and in the material of which it is constructed, by which all danger or inconvenience arising from the heat of the current is avoided.

The frame of this switch is composed of soapstone or other non-conductor of heat that can be readily worked in the desired form, and instead of resistances formed of metallic conductors, as in the patent above referred to, we employ either broken or powdered carbon or carbon'rods packed in tubes formed or set in the frame of the. switch.

Reference being had to the drawings, A is a disk of plaster of-paris, soapstone, or other the position they hold with respect to each other being clearly shown in Fig. 1, wherein the full lines represent the pieces I upon the 'top of the disk and the dotted lines the pieces J upon the under side of the disk. The enlarged ends of the pieces I J cover the holes N 0 through the disk, the pieces I acting as a stopper to the upper end of the hole. The hole being packed with carbon K, Fig. 4., the plunger L is put into the lower end, and by means of screw M in piecesJ the plunger Lis caused to exert any required pressure upon the carbon, thus making perfect connection with the carbon and enabling its resistance to be changed, if desired.

Through hole B passes a stud, B, drawn down upon the disk A by nut 13 on the under side of the disk, and turning upon this stud is a metallic disk, 0, Figs. 2 and 3, through the hole B of which the stud passes, the disk 0 being secured in place by nut 13", Fig. 2, on the upper end of stud B.

On the disk 0 are two brackets, 'D D, drilled partly through from the under side of the disk. In the circular cavities thus made, actuated by spiral springs E, work the two plungers E, which, as the disk is turned, make connection with the faces of the pieces I. The disk is further provided with eight pins, F, in which the pin G of crank-key Gr, working on stud H, engages, precisely the same as in the Letters Patent referred to. Referring to those Letters Patent, the current, as shown in Fig. 1, e11- ters from the side at the stud B, and thence through disk 0 and its plunger E, and when the lamp is not in circuit it passes outward by way of piece I (numbered 1) and the carbon resistance N, which has the same resistance as that of the lamp. Then the lamp is fully lighted the current passes outward by way of piece I, (numbered 14,) and through the lamp.

The object of the piece P is merely to keep the plungers E from dropping out of place. Supposing the resistance of the lamp is .95 ohm, the resistance N, Fig. 6, corresponding to piece I, No. 1, of Fig. 1, is .95 ohm. When the lamp is completely out of the circuit one of the studs E is bearing upon piece I, No. 1, and the other stud E is bearing upon the blank piece 1?, with which there is no connection. A single turn of the crank brings the studs upon pieces I, Nos. 2 and S, and the current divides, three-fourths of it flowing, by

' way of pieces 2, carbon resistance N, of

ohm, piece J, and. bolt 1, to piece I, No. 1, and resistance N, of .95 ohm, outward, and onefourth of it flowing, by way of piece 8, carbon resistance 0, of 1.9 ohm, and thence by piece J and-bolt I to piece 9; thence through carbon resistance 0, of .38 ohm, and so on through carbon resistances 0 of 25% ohm, O, of 18%,- ohm, O, of 07%, ohm, and 0 of 06% ohm, and thence, through piece J and bolt 1, to piece 14 and the lamp. The total resistance of the first or shunt circuit istherefore 1.26% ohm, and that of the lamp-circuit, including the lamp, is 3.8 ohms, making the joint resistance .95ohm. The resistance of N is 53% ohm, N 153% ohm, N 1.26% ohm, N

3.8 ohms, and N 7.6 ohms, makingasum total of resistances on the shunt side of 15.2 ohms.

Without following out the various changes, which are fully set forth in the Letters Patent referred to, suflice it to say that when one plunger E is bearing upon piece I, No. 1, the other plunger is bearing upon blank piece P,

. and that the plungers thereafter take position 229,476 BEST AVAILABLE COPY as follows: upon 2 and 8, 3 and 9, at and 10, 5 and 11, 6 and 12, 7 and 13, and lastly blank piece P and leigwhcn the entire current is directed through the lamp.

Having thus fully described our invention, we claim and desire to secure by Letters Patent- 1. An electric switch consisting of a frame composed of soapstone or plaster, or other insulating material, also suitable to resist the transmission of heat, fitted with carbon re- 

